1. Technical Field
The present disclosure relates to the field of integrated circuits. The present disclosure relates more particularly to integrated circuit packaging.
2. Description of the Related Art
Integrated circuits are used in a large variety of applications. Individual integrated circuits can take the form of voltage amplifiers, voltage regulators, digital signal processors, microcontrollers, wireless adapters, microprocessors, smart cards, and many other devices. Some integrated circuits have circuitry that performs many of these functions on a single chip.
Integrated circuits are installed in desk top computers, lap top computers, cell phones, MP3 players, automobiles, printers, scanners, wireless routers, and in nearly every other kind of electronic device. Integrated circuits are generally packaged in such a way that they can easily be installed in one of the above mentioned devices. Methods of packaging integrated circuits include the use of ball grid arrays (BGAs), pin grid arrays (PGAs), lead frames, and many other methods. The balls, pins, and leads of the various integrated circuit packages provide the electrical connections between the integrated circuit and the electronic device in which it is installed. Most kinds of integrated circuit packages include a molding compound that encapsulates the integrated circuit and protects it from damage and provides electrical insulation.
In many devices, individual packaged integrated circuits are stacked one on top of the other. This saves surface area in the electronic device but also leads to complications in electrically connecting the integrated circuits to each other and to the electronic device. In such devices the integrated circuit packages generally have electrical connections on a top surface and a bottom surface of the package. One method for connecting top and bottom surfaces of a package is to form vias through the semiconductor die to allow electrical connection of the top of the package to the bottom of the package. However this uses valuable surface area of the semiconductor die to make the vias.